Free piston inertia compressor

In a free-piston inertia compressor comprising a cylinder and a free-floating piston assembly disposed for reciprocation therein, the improvement wherein said piston assembly includes a smoothly tapered connecting rod having pistons on both ends of the rod, wherein the connecting rod has end portions of relatively large diameter, which smoothly taper to a central portion of relatively small diameter, the central portion providing free play of the connecting rod through a single fixed seal at the longitudinal center of the cylinder for effecting a seal alternatively to the large diameter end portions of the rod and allowing the venting of fluid from one side of the seal to the other and the end portions providing tolerance of less than 1 mil between the relatively large diameter portions of the connecting rod and said seal to the large diameter portions preventing the passage of fluids;

• wherein the seal is constituted by a seal assembly having a cylindrical dampener plate of greater diameter than the cylinder, said dampener plate having recesses therein into which are sealed the two halves of the cylinder, said dampener plate having an axial opening therein which accepts the connecting rod, one face of the dampener plate having a deep recess therein located at the center of the dampener plate, a floating seal ring disposed in said deep recess, the same face of the dampener plate having a shallow recess therein and a seal retainer plate fastened in said shallow recess.